001/* 002 * Licensed to the Apache Software Foundation (ASF) under one or more 003 * contributor license agreements. See the NOTICE file distributed with 004 * this work for additional information regarding copyright ownership. 005 * The ASF licenses this file to You under the Apache license, Version 2.0 006 * (the "License"); you may not use this file except in compliance with 007 * the License. You may obtain a copy of the License at 008 * 009 * http://www.apache.org/licenses/LICENSE-2.0 010 * 011 * Unless required by applicable law or agreed to in writing, software 012 * distributed under the License is distributed on an "AS IS" BASIS, 013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 014 * See the license for the specific language governing permissions and 015 * limitations under the license. 016 */ 017package org.apache.logging.log4j.core.appender.db.jpa.converter; 018 019import java.io.IOException; 020import java.util.Map; 021 022import javax.persistence.AttributeConverter; 023import javax.persistence.Converter; 024import javax.persistence.PersistenceException; 025 026import org.apache.logging.log4j.util.Strings; 027 028import com.fasterxml.jackson.core.type.TypeReference; 029import com.fasterxml.jackson.databind.ObjectMapper; 030 031/** 032 * A JPA 2.1 attribute converter for {@link Map Map<String, String>}s in 033 * {@link org.apache.logging.log4j.core.LogEvent}s. This converter is capable of converting both to and from 034 * {@link String}s. 035 * 036 * In addition to other optional dependencies required by the JPA appender, this converter requires the Jackson Data 037 * Processor. 038 */ 039@Converter(autoApply = false) 040public class ContextMapJsonAttributeConverter implements AttributeConverter<Map<String, String>, String> { 041 static final ObjectMapper OBJECT_MAPPER = new ObjectMapper(); 042 043 @Override 044 public String convertToDatabaseColumn(final Map<String, String> contextMap) { 045 if (contextMap == null) { 046 return null; 047 } 048 049 try { 050 return OBJECT_MAPPER.writeValueAsString(contextMap); 051 } catch (final IOException e) { 052 throw new PersistenceException("Failed to convert map to JSON string.", e); 053 } 054 } 055 056 @Override 057 public Map<String, String> convertToEntityAttribute(final String s) { 058 if (Strings.isEmpty(s)) { 059 return null; 060 } 061 try { 062 return OBJECT_MAPPER.readValue(s, new TypeReference<Map<String, String>>() { }); 063 } catch (final IOException e) { 064 throw new PersistenceException("Failed to convert JSON string to map.", e); 065 } 066 } 067}